QRCODE: use stricter interpretation of ZINT_FULL_MULTIBYTE, excluding
certain trailing bytes
libzint: fix some confusing error messages introduced by segment stuff
general: new escape chars \U, \d and \o
backend_qt: fudge rendering of border rectangles due to scaling/translation
rounding errors TODO: better fudge
GUI: foreground/background colours -> text boxes and icon buttons, add swap
button, independently movable picker (NULL parent), preview colour changes,
preview Data Window changes, add clear data (del) buttons, add zap button
and Factory Reset menu option, various other fixes
libzint: remove STATIC_UNLESS_ZINT_TEST, use wrappers
CMake: add find package QtSvg, remove QtXml
manual: split symbology and general specs and sort, move DAFT to 4-state,
UPC/EAN -> EAN/UPC, DataBar -> GS1 DataBar always, expand MAILMARK info,
various other fiddlings
man page: options or -> |, expand MSI Plessey check digit options
README.linux: add packages info
license: add SPDX-License-Identifier to touched files
and restrict sequence to max 10,000, add button icons;
make Export dialog sizable and show every 100 results, add button icon;
fix saving CHANNEL option, fix Export painting main window (Windows), fix
guard descent not-resetting
qzint: add getAsCLI(), warnLevel(), extra isStackable()/isComposite() etc
Add ZBarcode_BarcodeName()
manual: doc above, some fixes, tweaks
Rename barcode funcs to same as BARCODE_XXX name
library: barcode funcs array for dispatch, used for ZBarcode_ValidID() also
general: change is_sane() comparison to nonzero from ZINT_ERROR_INVALID_OPTION
MAILMARK: fuller error messages
CODABAR: add option to show check character in HRT
zint.h: use 0xNNNN for OR-able defines
GUI: add guard descent height reset button, add Zint version to window title,
static get_zint_version() method, use QStringLiteral (QSL shorthand),
use SIGNAL(toggled()), add errtxt "popup" and status bar, add icons,
add saveAs shortcut, add main menu, context menus and actions, add help,
reset_view() -> reset_colours(), add copy to clipboard as EMF/GIF/PNG/TIF,
lessen triggering of update_preview(), shorten names of getters/setters,
simplify/shorten some update_preview() logic in switch,
CODEONE disable structapp for Version S
qzint.cpp: add on_errored signal, add missing getters, add test
